CALLS have been made for a criminal probe following the latest allegations that the awarding of the ferries fiasco contract to Ferguson Marine was rigged.
Deputy First Minister John Swinney has said ministers were "not aware of any impropriety in the procurement process" while saying allegations will be looked into.
And Caledonian Maritime Assets Limited (CMAL), the Scottish Government-controlled firm that owns and procures CalMac’s ferries said there was "no evidence" to support new allegations.
But Scottish Conservatives shadow transport minister Graham Simpson said the police should be called in to investigate.
The BBC documentary claims that the shipyard under tycoon Jim McColl was allowed to change the design during the tendering process, making its pitch almost £10m cheaper. On the alleged change of bid, CMAL says that two bidders sought clarification which is a "normal step".
There was also a confidential meeting between the yard and CMAL – a courtesy not extended to other bidders in the process. But CMAL says that one face to face meeting was held with Ferguson. Other bidders participated in similar technical clarification engagement digitally given their non-UK locations.
It as also claimed that Ferguson's obtained a 424-page 'crib sheet' from a design consultant setting out CalMac's technical requirements, while other bidders had to rely on a more limited 125-page specification. But CMAL say this was not provided by them and that it seemed to be accepted that this was provided by an independent consultancy.
It also says that CMAL the Scottish Government-controlled firm that owns and procures CalMac’s ferries may have broken its own rules by allowing Ferguson to go ahead with its bid despite being unable to provide evidence of a builders refund guarantee, a mandatory financial safeguard.
The Herald revealed in May that Ferguson Marine failed to fulfil mandatory requirements to qualify as the ferry fiasco contract bidder raising fresh questions about the legality of the procurement process.
New evidence which showed that the tycoon's shipyard firm which was favoured by the SNP government could not give a commitment to provide a mandatory builder's refund as required and was unable to provide other crucial financial details including records of past achievements.
The fails were revealed in a confidential Pre-Qualification Questionnaire (PQQ) completed by Ferguson and seen by the Herald before it was ever even considered as a preferred bidder for the building of two lifeline ferries to serve Scotland's islands.
Particular focus has fallen on the failure of Ferguson to offer a builder’s refund guarantee, which would have protected public money once construction ran into problems - which it did.
The PQQ stated that an inability to meet mandatory requirements would result in exclusion not just from any future bidding process, but from the scoring exercise itself. That would mean failing at the first of what was a three-step procurement hurdle.
The guarantee had to be in place before work started and bidders such as FMEL had to provide an "evidentiary statement" in the form of a letter from the bank confirming a willingness to provide the guarantee "if requested to show you can provide this requirement".
But Mr McColl's Inverclyde-based shipyard firm was unable to give any make a firm commitment on the guarantee in the PQQ.
Yet Ferguson Marine remained one of six companies with the highest scores which were be taken forward to the tender stage before a preferred bidder was identified.
Another mandatory requirement that proved problematic involved the provision of a copy of audited accounts for the most recent two years and a statement of turnover, profit and cash flow for the most recent full year of trading.
Officially, the two vessels at the centre of Scotland's ferry-building scandal that remain at the Inverclyde yard will be delayed until at least next year – over five years later than planned while costs have risen by at least two-and-a-half times from £97m to £250m.
Mr Swinney said the allegations were "concerning" and said: "Scottish ministers are not aware of any impropriety in the procurement process, but take the claims made extremely seriously and it is important that they are carefully addressed. as I know that the current management team at CMAL and at Ferguson's share that concern.
"I've committed already that ministers would explore what the further steps the government needs to take to ensure that all questions about the fairness and appropriateness of the tendering process are properly independently investigated. I can confirm that the permanent secretary at the request of ministers has already proactively been in contact with the Auditor General to discuss this matter.
"The Auditor General informed the Permanent Secretary, that Audit Scotland will be looking at the substance of the allegations raised around procurement by the programme before deciding if further audit work is required. I welcome this. Scottish Government, CMAL and Ferguson's all commit to fully supporting that exercise."
Mr Simpson said: In short, it appears Ferguson's received special treatment from this government and its agencies. Special treatment that nobody else got. Special treatment that might have broken laws which could open the government to legal action.
This is a scandal. It looks like corporate corruption. And the fact we're only finding out now means it's been a cover up as well.
"So can the Deputy First Minister tell us who chose Ferguson to receive special treatment and why were the documents which we now know about kept hidden."
He added: "It is no use the Deputy First Minister hiding behind the Auditor General.
"If the government accepts this is wrong and they appear to do that, they don't know how it has happened or who's responsible, then surely, they must now call in the police to investigate.
"Because if Ferguson receives special treatment for whatever reason, it's beyond a scandal, it's a crime in my view.
"This alleged rigging of the contracts, potential fraud has cost the country £250m and it's rising. So will the government now call in the police so we can finally find out the truth of what has happened."
Mr Swinney said: "It is important that I place on the parliamentary record that CMAL have made clear to the BBC that they can find no trace of that (424 page) document going from CMAL to Ferguson's and it's important that these points of factual accuracy are put on the record.
"In relation to the wider questions that are raised. That is why I give the commitment that these new points of detail and information that have been raised by the BBC documentary need to be explored further.
"What I've been doing is asking the Permanent Secretary of the Scottish Government to raise with Audit Scotland the issues that have been put to us, to establish any further inquiry that is required to be undertaken and of course, what that would enable is independent scrutiny of the procurement process to be undertaken, as Audit Scotland do on countless other issues and have done on the Ferguson's contract already.
"So that is what I've been doing because I would have thought Parliament would want there to be a process of independent assessment of these issues, which can be properly considered and any appropriate action taken as a consequence."